Credit Card Interest Calculator
Enter your credit card balance, APR, and monthly payment to see your payoff timeline, the total interest you will pay, and a month-by-month amortization schedule. Switch to "target payoff" mode to find the exact payment needed to clear your debt by a specific date. Results update instantly as you type.
How credit card interest is calculated
Credit card issuers calculate interest using the Average Daily Balance (ADB) method in most cases. First, your APR is divided by 365 to get a daily periodic rate (DPR). That rate is applied to your average daily balance across the billing cycle. If your APR is 20%, the DPR is 20 / 365 = 0.0548% per day. On a $3,500 balance over a 30-day month the interest charge is roughly $57.53. Because the rate is applied daily, compounding means a 20% APR results in a slightly higher effective annual rate of about 22.1%. Paying even a modest amount above the minimum every month cuts the number of interest-bearing days and reduces the compound effect significantly.
Minimum payments and why they are costly
Credit card issuers typically set a minimum payment at around 1% to 2% of the balance plus that month's interest, or a flat amount (often $25 to $35), whichever is higher. On a $3,500 balance at 20% APR, a minimum payment of around $70 barely covers the interest charge, leaving almost nothing to reduce the principal. At that pace it can take over 20 years to clear the debt and cost more than $5,000 in interest. Increasing your payment by even $30 to $50 per month can shave years off the repayment period. This calculator lets you experiment with different payment amounts to see the impact immediately.
Payoff strategies: fixed payment vs. target date
Two approaches work well depending on your situation. With the fixed-payment mode you enter what you can afford each month and see when you will be free of the debt and the total cost. With the target-date mode you decide when you want to be debt-free and the calculator shows you the exact payment required to hit that goal. For example, to clear $3,500 at 20% APR in 24 months you need to pay about $178 per month and will pay roughly $775 in total interest. Extending to 36 months drops each payment to about $130 but raises total interest to around $1,170. Shorter terms cost less in interest even though the monthly commitment is higher.
Balance transfers and other payoff tactics
A balance transfer moves your existing balance to a new card that charges 0% APR for an introductory period, typically 12 to 21 months. If you can pay off the transferred amount before the promotional period ends, you avoid interest entirely. Watch for the transfer fee, usually 3% to 5% of the amount moved, and confirm the ongoing APR that kicks in afterward. Other strategies include the debt avalanche (paying highest-APR cards first to minimize total interest) and the debt snowball (paying smallest balances first for psychological wins). Either approach beats paying the minimum. This calculator works for any single card; for multiple cards, run the calculation separately for each and apply any surplus to the highest-rate balance.
Typical credit card APR ranges
| Card type | Typical APR range | Notes |
|---|---|---|
| Student / secured | 19% - 26% | Higher risk, limited credit history |
| Standard rewards | 20% - 27% | Cash back, points, miles cards |
| Balance transfer (promo) | 0% for 12-21 months | Reverts to standard APR after intro period |
| Retail / store card | 25% - 31% | Often the highest ongoing rates |
| Premium travel | 21% - 28% | High rewards offset by high APR |
| Business card | 18% - 27% | Varies by issuer and creditworthiness |
Average APRs by card type as reported by the Federal Reserve (2024-2025).
Frequently asked questions
How does daily compounding affect my credit card interest?
Most issuers apply interest daily, so the interest from one day is added to the balance and earns interest the next day. Over a full year, a 20% APR with daily compounding grows to an effective annual rate of about 22.1%, meaning you pay slightly more than the stated rate suggests. The effect is modest month-to-month but grows meaningfully when the balance is carried for years.
What is the minimum payment on a credit card?
Minimum payments are set by the card issuer, typically as the greater of a flat amount (around $25 to $35) or 1% to 2% of the outstanding balance plus that cycle's interest charges. Paying only the minimum keeps the account in good standing but can result in decades of repayment and thousands of dollars in total interest on even modest balances.
Will making extra payments really make a big difference?
Yes, considerably. Because interest compounds daily on your remaining balance, every dollar of principal you eliminate early saves interest for every subsequent day. On a $3,500 balance at 20% APR, increasing the monthly payment from $80 to $150 cuts the payoff time roughly in half and saves over $1,500 in total interest. Use the calculator to run your own scenario.
How does a 0% balance transfer card help?
A balance transfer card charges no interest during a promotional period (usually 12 to 21 months). If you transfer your balance and pay it off before the introductory period ends, you pay zero interest. Fees of 3% to 5% of the transferred amount typically apply, so weigh that against the interest you would pay by staying on your current card.
What APR is considered high for a credit card?
As of 2025, the average credit card APR in the United States sits above 20%. Anything above 25% is considered high, and retail or store cards frequently reach 28% to 31%. Cards below 15% are now rare and typically require excellent credit. The reference table in this calculator provides typical ranges by card type.
Does paying the statement balance in full each month eliminate interest?
Yes. If you pay the entire statement balance by the due date every month, you benefit from a grace period and no interest accrues on purchases. Interest charges only apply when you carry a balance from one cycle to the next. Cash advances are an exception: they typically start accruing interest immediately with no grace period.